There's not that many jobs where the Mac Pro, or a Xeon Workstation in general, is actually necessary. 4k video editing and professional 3D modeling and animation are some of the more common ones. So if you're doing one of these it might be worth it, but otherwise it's just overkill and you might as well just get yourself an iMac.
As for the talk about the highest end Macbook Pro being just as fast, it's simply not as fast. The CPU on the cheapest Mac Pro crushes the Macbooks' and just one of the two GPU's even in the baseline Mac Pro beats the one in the Macbook with a solid margin. The most probable reason for this misconception is that the top-of-the-range Macbook Pro comes with a 512 GB SSD, the baseline Mac Pro with a 256GB one, and with Apple higher capacity SSD's are faster. The 256GB SSD is a 2 lane PCIe drive while the 512GB model is a 4 lane PCIe one. Just upgrade from 256 to 512 is just a $300 optional extra whereafter the Mac Pro leaves the Macbook in the dust.